Positive steam flow control in condensers



1962 R. c. DEAN, JR., EI'AL 3,061,273

POSITIVE STEAM FLOW CONTROL IN CONDENSERS Filed May 19, 1958 2 Sheets-Sheet 1 N r0 E INVENTORS ROBERT C. DEAN JR.

ARTHUR .SHAV/T THEIR ATTORNEY Oct. 30, 1962 R. c. DEAN, JR., EIAL 3,06 73 POSITIVE STEAM FLOW coumor. IN CONDENSERS Filed May 19, 1958 2 Sheets-Sheet 2 0 G0 (I O oooaa a a no QQIQ THEIR ATTORNEY United States Patent 3,061,273 POSITIVE STEAM FLOW CONTROL IN CONDENSERS Robert C. Dean, Jr., Easton, Pa., and Arthur Shavit,

Brookline, Mass., assignors to Ingersoll-Rand Company,

New York, N.Y., a corporation of New Jersey Filed May 19, 1958, Ser. No. 736,226 4 Claims. (Cl. 25743) This invention relates to improvements in condensers and in particular to surface condensers for condensing steam and other vapors.

An object of the invention is to provide a condenser of the surface type in which the heat transfer is effected in a more efficient manner than heretofore.

Another object is to provide a condenser of the surface type in which effective steam distribution is obtained with a relatively low pressure drop between the inlet and outlet of the condenser.

Another object of the invention is to provide a condenser of the surface type including features of construction for accomplishing a positive control of the steam flow within the condenser.

Still another object of the invention is to provide a condenser of the surface type including improved structural features for securing more effective and more economical operation.

A further object of the invention is to provide a condenser of the surface type including structural features which make it possible to reduce the condenser volume and consequently the total Weight and physical size of a condenser required for operation at a given capacity.

Another object of the invention is to provide a condenser of the surface type having an improved arrangement for distributing the steam or other vapors supplied to the condenser and for increasing the effectiveness of the full surface area of the cooling tubes.

Still another object of the invention is to provide a condenser of the surface type including improved features of construction for more economic use to be made of the cooling tubes.

Another object of the invention is to provide a con denser of the surface type in which the aeration or the removal of non-condensible gases can be achieved with increased effectiveness.

A particular object of the invention is to provide a condenser of the surface type in which the steam or other vapor is directed in separate but communicating paths throughout the condenser.

Still another object of the invention is to provide a condenser of the surface type including improved'structural features to prevent the formation of stagnant pockets in the path of the steam through the condenser.

These and other objects and features of the invention will be apparent from the following specification when read in conjunction with the accompanying drawings,

wherein:

FIGURE 1 shows a part of the condenser in end elevation with a portion of the water box broken away and shown in cross section to illustrate details of the improved tube arrangements and shielding of the steam lanes with the cross sectional pattern of the condenser tubes shown diagrammatically by center lines,

FIG. 2 is a view showing a part of the condenser in vertical longitudinal cross section along the line 22 of FIG. 1 looking in the direction of the arrows,

FIG. 3 is an enlarged fragmentary cross section through a group'of tubes showing in detail the arrangement of the sheet metal shields and the louvered openings therein,

3,061,273 Patented Oct. 30, 1962 FIG. 5 is a view showing the arrangement of cooperating bafiles of two groups of tubes.

Conventional steam condensers in steam generating plants are of a substantially heavy structure and costly to manufacture, and efforts have been made to reduce the condenser size, weight and cost. In order to achieve a reduced condenser volume, an improvement in the flow conditions in the condenser shell has been considered and this has resulted in an improved condenser structure in which a reduction in flow area, and consequently, a more compact tube bundle arrangement, relative to the tube bundle arrangement in conventional types of condensers, is provided.

In conventional type of condensers the flow of steam is directed by the arrangement of the tubes relative to each other and sufiicient flow area has to be provided to permit the flow of steam to follow a path of natural flow through the tube bank in order that each tube may perform its share of condensation. With the provision of a natural path of flow of the steam in a conventional condenser a necessary flow area is required with respect to steam velocities to achieve a high efficiency of heat transfer.

To achieve a reduction in flow area, and consequently, a reduced condenser volume as compared to that of a conventional condenser for a given steam flow at specified entry steam perssure and cooling water temperature, this invention provides an improved arrangement of the tubes and shielding of the steam lanes to create a positive control of the flow of steam within the condenser.

It is to be noted that the reduction in flow area has been accomplished Without substantially changing the relatively low pressure drop of the steam during its passage through the condenser and without reducing the heat transfer efiiciency of the tubes. v

Referring more in detail to the figures of the drawing, the condenser 10, according to the invention, is provided with a pair of condenser tube banks of which one tube bank 12 is shown having a plurality of tubes 14 arranged in longitudinally extending relation throughout the length of the shell 16.

For reasons of simplicity the condenser is illustrated with only one tube bank in cross section, see FIG. 1, as the other tube bank is formed with the tubes arranged in the same but opposite way. The opposite ends of the tubes.14 are secured in tube sheets of which one tube sheet 18 is shown such that the tubes 14 open on the outside faces of the tube sheets in a Way well known in the art. The condenser tubes, indicated by the numeral '14, and the illustration of the tube bank 12 and groups of tubes 20 in the drawing is diagrammatic due to the small scale required for illustration. Circles have been drawn on some of the tube centers outlining the tube bank 12 and groups of tubes 20 to facilitate the illustration of the improved arrangement of the tubes 14 and the shielded steam lanes 22 in the condenser 10.

In the present embodiment of the invention the conventional system of double row and triple row fan tube arrangements has been modified and a system of multiple row tube arrangements has been substituted. Each tube bank 12 is divided into a plurality of column shaped groups of about ten rows of tubes wide each. According to the invention the spacing of the groups of tubes 20, relative to each other, is less than that used in con ventional practice. In other words, for a given condenser capacity, the total width of the tube bank 12, i.e., the

FIG. 4 is a view showing a baffle arrangement over the v upper end of a group of tubes, and

total width of the lanes 22 and the total width of the groups of tubes 20, is less than the total width of the tube bank in a conventional condenser.

Steam lanes 22 are formed between consecutive groups of tubes 20 and as clearly shown in the drawing each steam lane 22 is funnel shaped and converging from the inlet end 24 towards the outlet end 26 of the steam lane 22. As the steam flows from the inlet 28 of the condenser lt) through the steam lanes 22 towards the bottom 30 of the condenser 10, it has to flow to the inner parts of the groups of tubes 2% in order to feed the tubes 14 therein. It is obvious that, in a wide group of tubes, the steam velocity in that particular group of tubes must be kept sufficiently high if the tubes are to be entirely swept free of the air blanket. In order to achieve this an arrangement of sheet metal shields including diffusers and rejection nozzles is provided and adapted to effect a steam flow of a predetermined velocity through the associated groups of tubes. It is to be noted that with this arrangement air blanketing is prevented, air blanketing being a rather common occurrence in all condenser systems in which a certain amount of air is accumulated around the tubes as the steam condenses consequently causing a reduction in heat transfer.

As shown in the drawings, the sheet metal shields 32 are arranged along the entire length on both sides of the groups of tubes 20 concerned and extend substantially parallel with respect to the sides of the groups of tubes 20 towards the bottom 30 of the condenser 10. For maintaining a predetermined steam velocity in a wide group of tubes 20, a positive control of flow of steam across the group of tubes 2% is created by diffusing the steam through the shield 32 on one side of the group of tubes 20 and rejecting it through the shield 32 on the other side of the group of tubes 25) into the adjacent steam lane 22.

The diffusers and rejection nozzles are provided by punching louvered openings 34 in each sheet metal shield 32 as shown in FIGS. 2 and 3. The diffusers and rejection nozzles are adapted to permit the steam flowing across the groups of tubes 20 to maintain a predetermined velocity and pressure above the pressure of the steam in the adjacent steam lanes. It is to be noted that the arrangement of the louvered openings 34 is staggered as shown in FIGS. 2 and 3. The louvered openings 34 in the shield 32 for diffusing the steam in the group of tubes 20 will preferably have their sloping portion 36 protruding in the steam lane 22 and opening towards the flow of steam from the inlet end 24 of the associated steam lane 22 in order to deflect the flow of steam from the steam lane 22 into the group of tubes 20. The louvered openings 34 in the shield 32 for rejecting the steam from the group of tubes 26 into the adjacent steam lane 22 are used to aid in the control of pressure and velocity in the group of tubes 20 and will preferably have their sloping portion 36 protruding in the adjacent steam lane 22 and opening towards the outlet end 26 of the steam lane 22 in order to deflect the flow of steam from the group of tubes 20 parallel to the flow of steam in the adjacent steam lane 22.

In operating the condenser of the character shown in the drawings the steam admitted to the condenser 10 flows downwardly at high velocity and in substantial quantities, striking the outer and primary surfaces of all the tubes 14 within its path. By reason of the construction of the condenser 10 the steam spreads out within the top of the condenser 10 over the tube banks 12 and a portion of the steam will penetrate the groups of tubes 20 at the top thereof while the other portion of the steam will flow through the shielded steam lanes 22 downwardly towards the bottom 39 of the condenser 10.

As the steam passes downwardly through the steam lanes 22 the louvered openings 34 in the sheet metal shield 32, adapted to act as diffusers, will deflect the flow of steam from the steam lane 22 and diffuse it in the group of tubes 20 in which it flows between the slantwise arranged tubes 14 across the group of tubes 20 towards the opposite shield 32. The shield 32 with its louvered openings 34 adapted to act as rejection nozzles will deflect the flow of steam from the group of tubes 20 and reject it into the adjacent steam lane 22 parallel to the flow of steam therein. The positive control of steam flow through the group of tubes 26 wirl ensure that the tubes 14 at the bottom 30 of the tube bank 12 are steam swept as well as those at the top of the tube bank 12. The air blanket which tends to form as the steam condenses, is swept off the tubes 14 and the whole tube surface is rendered effective for condensation of steam.

It is to be noted that a positive control of the flow of steam across the groups of tubes 20 can also be accomplished by arranging the tubes 14 in such a pattern that the tubes 14 at the diffuser side of a group of tubes 20 will effect the deflection of the flow of steam to conduct it from a steam lane into an associated group of tubes 29, while the tubes 14 at the rejection side of that group of tubes can be positioned to effect the deflection of the steam from that group of tubes into the associated steam lane. This arrangement achieves substantially the same effect as the louvered openings 34 in the shields 32 discussed before. As an alternative, vane type deflectors or bafiles may be arranged at the opposite sides of the groups of tubes to achieve the above mentioned effect.

Referring in particular to the rejection of the steam from the groups of tubes 29 this can also be accomplished by obstructing the flow of steam as it passes between the slant-wise arranged tubes 14 through the end portion thereof. This obstruction is preferably in the form. of a tube positioned in the flow path of the steam in the end portion of the passage between the slant-wise arranged tubes 14. The effect of rejection, an increase of velocity of the ejected steam flow, and maintenance of the steam pressure in the group 20 above the pressure in the associated steam lane 22, may also be accomplished by positioning the tubes 14 in such a pattern that the flow area in the end portion of the aforementioned passage is decreased.

With the improvement of the flow conditions in the condenser 10 with respect to the reduction in flow area and the use of shielded steam lanes 22, it is clear that the utilization of the steam velocity at the steam inlet of the condenser 10 is of paramount importance. In view thereof, an efllcient distribution of the steam to the steam lanes 22 can be accomplished by extending the shields 32 into the steam inlet of the condenser 10. As shown in FIG. 5, the shields 32 of each group of tubes 20 cooperatively form a baffle 38 to shield the upper part of the groups of tubes 20, the baflles 38 of consecutive groups of tubes cooperatively forming a nozzle shaped inlet 40 to conduct the steam into the associated steam lanes 22. The bafllles 38 are provided with openings 42 which serve to control the flow of steam into the upper part of the groups of tubes 20. In the condenser structure shown in FIG. 1, shielding of the upper end of the groups of tubes 20 may also be accomplished by providing a sheet metal baffle 44 positioned over the upper row of tubes of the groups of tubes 20, see FIG. 4, having openings 46 therein for the above mentioned control of steam flow.

It will be understood that the arrangement of the wide column shaped groups of tubes 20 in the tube banks 12, the provision of a reduced spacing of the groups of tubes 20 to form a more compact tube arrangement at the top of the condenser, the shielding of the steam lanes 22, and the velocity maintaining system of diffusing and rejection nozzles in the shields 32 will considerably increase the efliciency of the present condenser 10 over condensers heretofore known in the art. Furthermore, in addition to the improvements stated above a considerable reduction in condenser volume and consequently a considerable reduction in condenser size, weight and cost will be obtained by the system of shielding, positive steam-flow control and minimum spacing of the groups of tubes in the condenser.

It is to be understood that condensers designed in accordance with the disclosure herein may also find application for condensing vapors of other types than steam.

It is also to be understood that the invention is not to be restricted to the details set forth since these may be modified within the scope of the appended claims without departing from the sprit and scope of the invention.

We claim:

1. In a surface condenser comprising a shell having a steam inlet and a condensate outlet, a plurality of spaced condenser tubes divided into a plurality of groups of tubes disposed in said shell, said groups of tubes being spaced from each other and arranged to cooperate with each other to form a converging steam iane between consecutive groups of tubes, at least one of said groups of tubes provided with a baflie arranged to shield the upstream end of said one group of tubes, each steam lane having an inlet end and an outlet end for steam, each steam lane converging from said inlet end towards said outlet end, said one group of tubes provided with perforated shields arranged along the opposite sides of the length of said group of tubes, means on one of said shields to deflect the flow of steam from the steam lane adjacent the last said shield to the perforation of said one of said shields, and means on the other of said shields to deflect the flow of steam after said steam flows through the perforation of said other of said shields from said one group of tubes.

2. In a surface condenser comprising a shell having a steam inlet and a condensate outlet, a plurality of spaced condenser tubes divided into a plurality of groups of tubes disposed in said shell, said groups of tubes being spaced from each other and arranged to cooperate with each other to form a converging steam lane between consecutive groups of tubes, at least one of said groups of tubes provided with a baffle arranged to shield the upstream end of said one group of tubes, and at least one opening in said baflle to conduct steam from said steam inlet into said group of tubes, each steam lane having an inlet end and an outlet end for steam, each steam lane converging from said inlet end towards said outlet end, said one group of tubes provided with perforated shields arranged along the opposite sides of the length of said group of tubes, means on one of said shields to deflect the flow of steam from the steam lane adjacent the last said shield to the perforation of said one of said shields and into said one group of tubes, and means on the other of said shields to deflect the flow of steam after said steam flows through the perforation of said other of said shields from said one group of tubes.

3. -In a surface condenser comprising a shell having a steam inlet and a condensate outlet, a plurality of spaced condenser tubes divided into a plurality of groups of tubes disposed in said shell, said groups of tubes being spaced from each other and arranged to cooperate with each other to form a converging steam lane between consecutive groups of tubes, each steam lane having an inlet end and an outlet end for steam, each steam lane converging from said inlet end towards said outlet end, at least one of said groups of tubes provided with shields arranged along the opposite sides of the length of said group, the shields of said one group of tubes extending from said steam inlet towards the outlet end of said steam lane, and said shields cooperating to form a baffle to shield the upstream end of said one group of tubes, first openings in one of said shields to conduct steam from the steam lane adjacent the last said shield into said one group of tubes, and means to deflect the flow of steam from an adjacent steam lane to said first open- ,ings, second openings in the other of said shields to conduct steam from said one group of tubes, and means to deflect the flow of steam after said steam flows from said second openings.

4. In a surface condenser comprising a shell having a steam inlet and a condensate outlet, a plurality of spaced condenser tubes divided into a plurality of groups of tubes disposed in said shell, said groups of tubes being spaced from each other and arranged to cooperate with each other to form a converging steam lane between consecutive groups of tubes, each steam lane having an inlet end and an outlet end for steam, each steam lane converging from said inlet end towards said outlet end, at least one of said groups of tubes provided with shields arranged along the opposite sides of the length of said group, the shields of said one group of tubes extending from said steam inlet towards the outlet end of said steam lane, and said shields cooperating to form a battle to shield the upstream end of said one group of tubes, at least one opening in said baffle to conduct steam from said steam inlet into said one group of tubes, and means to deflect the flow of steam to said opening, first openings in one of said shields to conduct steam from the steam lane adjacent the last said shield into said one group of tubes, and means to deflect the flow of steam to said first openings, second openings in the other of said shields to conduct steam from said one group. of tubes, and means to deflect the flow of steam after said steam flows from said second openings.

References Cited in the file of this patent UNITED STATES PATENTS 1,662,155 Lucke Mar. 13, 1928 1,662,186 Grace Mar. 13, 1928 1,711,332 Spiess Apr. 30, 1929 1,855,231 Grace Apr. '26, 1932 1,927,095 Lucke Sept. 19, 1933 2,830,797 Garland Apr. 15, 1958 FOREIGN PATENTS 261,437 Great Britain Nov. 12, 1926 329,975 Great Britain May 28, 1930 444,484 Germany May 21, 1927 

